1. Field of the Invention
The present invention relates to automated downhole tools that are remotely movable between a primary and a secondary position. Particularly, the invention relates to computer control of automated downhole tools using an interactive computer touch-screen to facilitate use of a control system that operates the tools. More particularly, the invention relates to a means of monitoring the operation of the downhole tools using computer software to compare variables to known standards.
2. Description of the Related Art
In oil and gas wells, hydrocarbons are collected from at least one wellbore formed in the earth by drilling. In some cases, the wellbore is lined with steel pipe called casing or liner that is perforated at a given location to permit the inflow of hydrocarbons. In other instances, the wellbores are left unlined or “open” to facilitate the collection of hydrocarbons along a relatively long length of the wellbore. When hydrocarbons are collected at different locations within the well, it is useful to control the inflow of the fluid between the different points along the wellbore in order to take advantage of changing wellbore conditions. For example, inflow devices with adjustable sleeves can be placed at different, isolated locations in a tubular string. The sleeves in these devices have apertures formed therethrough that can be placed in or out of alignment with mating apertures in the body of the tool. By adjusting the relative position of the apertures, the sleeves can permit a varying amount of fluid to pass into a production stream for collection at the surface. The ability to control inflow is especially important along a wellbore where the make up of the incoming fluid can change over time. For example, if an unacceptable amount of water begins flowing into production tubing at a certain location, an inflow device at that location can be partially or completely closed, thereby preventing the water from entering the production stream.
Some prior art inflow devices require the sleeves to be set at the surface of the well based upon a prediction about the wellbore conditions. After run-in, changing the position of the devices requires them to be completely removed from the well along with the string of tubulars upon which they are installed. More recently, the inflow devices have been made to operate remotely using hydraulic fluid transported in a control line or some electrical means to shift them between positions. In the most advanced applications known as “Intelligent Completions”, the devices are computer controlled, permitting them to be operated according to a computer program.
A typical computer-controlled apparatus for the operation of downhole inflow devices includes a keyboard that is connected to a computer; solenoid-controlled valves that open to permit control fluid to travel down to the device in the wellbore; a pump; a source of control fluid; and at least two fluid lines traveling downhole to a fluid powered controller that determines which of the more than one hydraulic/mechanical inflow device is supplied with the control fluid. Typically, the controller includes some type of keyable member that can align or misalign fluid ports connected to the devices therebelow. Each such device has at least one fluid line extending from the fluid controller, but may require a multiplicity of fluid lines. The fluid lines provide fluid to the device and a path for return fluid back to the surface. In one arrangement, the computer at the surface provides a source of fluid at a relatively low pressure that can shift an internal valve mechanism in the controller in order to set up a particular alignment of ports to supply control fluid to the proper downhole device. Once the fluid controller is properly arranged, control fluid is provided at a second, higher pressure to the particular device in order to move a shiftable sleeve from its initial position to a second position. In this manner, each device can be operated and separate control lines for each device need not extend back to the surface.
While the computers have made the devices much more useful in wells, there are some realities with computer equipment at well locations that make their use difficult and prone to error. For example, personnel at a well are not typically trained to operate computer keyboards and even the most straightforward commands must be entered with the keyboard, posing opportunities for error. Even the use of a computer mouse requires precise movements that are difficult in a drilling or production environment. Additionally, environmental conditions at a well include heat, dirt, and grime that can foul computer equipment like a keyboard and shorten its life in a location where replacement parts and computer technicians are scarce.
Another issue related to computer-controlled equipment is confirming that the orders given to a downhole device via computer have actually been carried out. For example, in computer-controlled systems, a command is given for a downhole tool to move from one position to another. Ultimately, the software command is transmitted into some mechanical movement within the tool. While there might be a computer-generated confirmation that the command has been given, there is no real way of immediately knowing that the prescribed physical action has taken place. In some instances, movement within a tool is confirmed by monitoring the well production to determine if the flow has been affected by the closing of an inflow device. This type of confirmation however, is time consuming and uncertain.
There is a need therefore for a computer control system that is easier to use when operating automated downhole tools in a wellbore. There is a further need for an apparatus and method of quickly and easily ensuring the automated computer commands to downhole equipment have been carried out.